Backlight Unit - Acer D240H Service Manual

5.2 Backlight Unit

Parameter guideline for CCFL Inverter is under stable conditions at 25
Parameter
CCFL Standard Current (ISCFL)
CCFL Operation Current (IRCFL)
CCFL Frequency (FCFL)
CCFL Ignition Voltage (ViCFL, Ta= 0 )
CCFL Ignition Voltage (ViCF, Ta= 25 )
CCFL Operation Voltage (VCFL)
CCFL Power Consumption (PCFL)
CCFL Life Time (LTCFL)
Note 1: Typ. values are AUO recommended design values.
*1 All of characteristics listed are measured under the condition using the AUO test inverter.
*2 It is recommended to check the inverter carefully. Sometimes, interfering noise stripes
appear on the screen, and substandard luminance or flicker at low power may happen.
*3 While designing an inverter, it is suggested to check safety circuit very carefully. Impedance
of CCFL, for instance, becomes more than 1 [M ohm] when CCFL is damaged.
*4 Generally, CCFL has certain delay time after applying kick-off voltage. It is recommended to
keep on applying kick-off voltage for 1 [Sec] until discharge.
*5 Reducing CCFL current will increase CCFL discharge voltage and generally increases CCFL
discharge frequency. So all the parameters of the inverter should be carefully designed so
the inverter will not produce too much leakage current from high-voltage output.
*6 Both CCFLs in the CCFL set (2 CCFL lamps on each side of a panel) is designed for
identical phase driving. Reversed phase driving of CCFL set is not encouraged.
*7 For designing CCFL current, it is highly recommanded to use symmetric and consistent
sinusoidal wave for each CCFL input current with asymmetric ration of 10% or less in both
postive area and negative area (ie. 0.9*√2*I
following diagram, otherwise proper CCFL functionality cannot be guarantied.
document version 1.0
NUMPAGES |29}
Product Specification
AU OPTRONICS CORPORATION
Min.
7.0
3.0
40
2000
℃
1850
℃
-
-
40,000
℃
Typ. Max.
7.5 8.0
7.5
8.0
53 60
- -
- -
900
-
(@7.5mA)
27 -
50,000
-
< I & I < 1.1*√2*I
rms 1 2
M240HW01 V2
(Room Temperature):
Unit Note
[mA] rms
[mA] rms
[KHz]
3, 4
[Volt] rms
[Volt] rms
[Volt] rms
[Watt]
[Hour]
) as refer to the
rms
14
2
5
6
7